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As Nick pointed out in a recent post, it’s hard to win close when a baseball team’s bullpen is among the very worst in the game, so it’s not surprising to see that the Brewers are 15-17 in 1-run games. The bullpen’s 4.60 ERA ranks 27th in MLB at the break, and not one regular reliever is under 3.96. It’s especially been a source of angst over the last month, when the team lost a string of close games largely as the result of repeated bullpen failures. The team has blown 14 “save” opportunities, the second highest mark in all of MLB.

Just why is this happening? Well, the reasons aren’t really too mysterious. For starters, they’re allowing too many base runners to reach safely. They have the highest WHIP (Walks+Hits/Innings Pitched) in the game. Allow a lot of men on base and you’re going to give up a good number of runs. The issue most firmly in their control is the fact that, as a pen, they’re 26th in walks per 9 innings, having allowed 4.00. Those are some grisly numbers too be sure, but as bad as they’ve been, there are some pretty good reasons for optimism going forward.

First of all, as much as the free passes have hurt them, the bigger problem as been that they’ve simply allowed a large number of hits. Some of that is teams squaring up balls, but some of it is just plain random variance. They have the very worst BABIP in the game, an unsightly .341 mark. That can partly be explained by the large number of line drives they’ve allowed, their 24.5% mark is the highest of any bullpen according to Fangraphs. The problem with simply saying that their high BABIP is the direct and sole result of the high line drive percentage is two fold. First off, the way that line drive percentage is calculated is somewhat open to question. Beyond that, though, is the simple fact that high line drive rates don’t automatically lead to high BABIP’s. Given all that, there seems to be a very strong chance that the bullpen’s BABIP drops, perhaps significantly, in the second half and that will lead to fewer total base runners.

It’s especially interesting to see that the team has allowed so many hits when one considers that, as a unit, they’re 6th in K/9 at 9.03. The guys have the raw stuff to dominate hitters and miss their bats, and they’ve done it often enough this season. What’s more, when balls are put in play, 47.5 percent of the time they’re on the ground, and that’s good for 7th best in the league. Ground ball percentages have some of the same problems as line drive percents (not all are created equal and perspective matters) but, in general, it’s safest for a pitcher if batters are putting balls on the ground instead of in the air. It’s also worth noting that the mid season additions of Tyler Thornburg and Livan Hernandez figure to negatively effect ground ball rate if they start seeing sizable numbers of innings.

Getting back to the idea of hitters putting balls in the air, it may seem as though the Brewers relievers have allowed a lot of home runs this year, but the reality is is they’re actually very much middle of the pack (13th) in home runs per 9 innings at 0.93. One can make a pretty strong case that they shouldn’t even be that bad, though, as they’ve also allowed the 7th highest number of home runs to fly balls. In other words, even though they’ve done a pretty good job of keeping balls down on the ground, when they’ve been up they’ve gone out of the park at a higher-than-expected rate.

Finally, there is the not so little matter of leaving runners on base. It’s not something the Brewers relievers did very often in the first half, as their 27th ranked 69.5 left on base percentage can attest. That is more than 5 percentage points lower than the league average of 74.8% in 2012. While low LOB numbers will often be chalked up to pitchers failing to pitch well out the stretch or other such controllable things, Fangraphs points out in their definition of the stat that outlying LOB numbers are often prone to regression.

That last link from Fangraphs contains a particularly interesting sentence that sums up pretty well what the Brewers bullpen has been through so far this year:

By using this statistic in conjunction with others — specifically BABIP and HR/FB — it’s possible to get an idea of if a pitcher is under- or over-performing and likely to regress.

The Brewers bullpen has the league’s worst BABIP, it’s 7th worst home run to fly ball ratio and 4th worst strand rate. That is one hell of a trifecta and a profoundly #Brewers2012 thing, but it just doesn’t seem to be very sustainable in the long run. If the team that seemed determined to exemplify Murphy’s Law in the first half, the bullpen certainly exemplified the team. The question before us is, can adding Tyler Thornburg and the baseball gods deciding that the Brewers relievers have done their share of suffering be enough to get the team over the hump, or will some other set of disasters befall a team that has seen more than it’s fair share? Only time will tell, but betting on the bullpen to stay as bad as it was in the first half seems a likely loser.